Answer:
The equation
represents the equation of the parabola with focus (-3, 3) and directrix y = 7.
Step-by-step explanation:
To find the equation of the parabola with focus (-3, 3) and directrix y = 7. We start by assuming a general point on the parabola (x, y).
Using the distance formula
, we find that the distance between (x, y) is

and the distance between (x, y) and the directrix y = 7 is
.
On the parabola, these distances are equal so, we solve for y:

Answer:
x - 8y - z = 1
Step-by-step explanation:
Data provided according to the question is as follows
f(x,y) = z = ln(x - 8y)
Now the equation for the tangent plane to the surface
For z = f (x,y) at the point P
is

Now the partial derivatives of f are


= 1
Now

= -8
So, the tangent equation is

Now after solving this, the following equation arise
z = x - 9 - 8y + 8
z = x - 8y - 1
Therefore
x - 8y - z = 1
Answer:
5400
Step-by-step explanation:
6x900 =5400 this is the correct answer
I'm assuming the funds earn 5% yearly?
Call x the amount he saves every year. The first year's deposit will be multiplied by 1.05 three times, the next will be multiplied by 1.05 twice, the third will be multiplied by 1.05 once, and the fourth will not generate interest (as it will immediately be used to buy the car).
Therefore, x(1.05^3+1.05^2+1.05+1)=21000, so 4.31x=21000. Dividing by 4.31, we see that x is approximately equal to 4872.

The last choice is appropriate.